The use of floatation devices for buoyantly supporting a helicopter on a body of water has been prevalent for many years. Some helicopters are equipped with fixed utility floats that do not require inflation. Others are equipped with inflatable floatation bags that are disposed deflated upon the landing skids or within compartments on the helicopter. These floatation bags are inflated in order to support the helicopter when ditching or landing in water is anticipated. Typically, the floatation bags are fixedly attached to the helicopter landing skids and packed tightly within flexible fabric covers. However, such systems are inadequate for use on helicopters that utilize landing gear rather than skids. As a result various other floatation systems have been integrated into fuselage compartments and/or compartments coupled to other portions of the aircraft, such as non-retractable landing gear. The floatation bags are only inflated if an emergency landing on water is expected. Conventional helicopter floatation bags suffer from a variety of shortcomings, some of which are discussed below.
For example, U.S. Pat. No. 3,507,466 discloses a helicopter undercarriage including a pair of floatation bags attached to the landing skids. The preferred embodiment discloses the floatation bags disposed underneath the landing skids. A drawback with this configuration is that the floatation bags will likely be ruined if the helicopter lands on a muddy marsh area, e.g. instead of open water. Further, since the floatation bags completely surround the landing skid, they will become worn and possibly damaged during each normal landing. Furthermore, the inflatable envelope structures are integrated onto the landing skids so that their removal would be time consuming and would likely required a heavily-trained technician.
Another example is U.S. Pat. No. 4,655,415, which discloses a helicopter floatation pack disposed on top of the landing skids. A drawback with this configuration is that the floatation pack must be attached to a landing skid so that it is above the skid. As a result, the installed floatation pack may limit access to the fuselage. In addition, because the structural member provides the support for a float pack cover, inflation fittings and the floatation bags, removal of the structural member from the landing skid requires removal of the entire flotation pack from the aircraft. As a result, additional handling is required during maintenance and packing to manipulate all of those components.
Another example is RU 2191129, which discloses a helicopter that includes inflatable floats. The system includes a two pairs of front and rear floats. The front floats are secured in the nose portion of the fuselage and the rear floats are mounted adjacent rear landing gear. A compressed gas system is used to inflate the floats when required, which includes high-pressure bottles housed in containers that are suspended from the underside of the fuselage. Pressure lines extend from the gas bottle containers to the floats. A disadvantage of the system is that the float housings appear to require that the floats be folded during the process of inserting them into the containers.
In view of these shortcomings, there exists a need for a helicopter floatation system that employs a float pack assembly that may be easily installed and/or removed from the remainder of the floatation system.
Any publications that are discussed above should not be taken as an admission that the publications are prior art.